Diisopropylethylamine → [2-(3-Bromo-imidazo[1,2-b]pyridazin-6-ylamino)-ethyl]-methyl-carbamic acid tert-butyl ester

Participants

Reaction Steps

A solution of 3-bromo-6-fluoro-imidazo[1,2-b]pyridazine (1.4 g, 6.3 mmol), N-(2-aminoethyl)-n-methyl carbamic acid tert-butyl ester [121492-06-6] (961 mg, 5.5 mmol), and Hunig's base [7087-68-5] (1.1 mL, 6.4 mmol) in 2-propanol (28 mL) was heated to reflux for 4d, cooled, preloaded onto silica gel and flash chromatographed (silica gel eluted with 10% (v/v) methanol/ethyl acetate). The isolated light yellow solid product was recrystallized (ethyl acetate/heptane) to yield 1.2 g of [2-(3-bromo-imidazo[1,2-b]pyridazin-6-ylamino)-ethyl]-methyl-carbamic acid tert-butyl ester as a white powder, mp. 128-129° C. 1H NMR (400 MHz, DMSO-d6) δ ppm (rotamers present) 1.16 (s, 6H) 1.33 (br. s., 3H) 2.84 (s, 2H) 2.90 (br. s., 1H) 3.34-3.44 (m, 3H) 3.45-3.52 (m, 1H) 6.68 (d, J=9.60 Hz, 1H) 7.31 (br. s., 1H) 7.49 (s, 1H) 7.72 (d, J=9.35 Hz, 1H). 13C NMR (100 MHz, DMSO-d6) δ ppm 28.22, 28.45, 34.02, 35.07, 39.02, 39.97, 46.23, 47.06, 78.52, 78.87, 99.57, 113.35, 125.92, 130.80, 137.01, 154.37, 155.39. LRMS (ESI) m/z 370.1/372.1 [(M+H)]+, calc'd for C14H20BrN6O2: 370.25.

Provenance & Evidence